Process and apparatus for forging cable tool drill bits



. May 23, 1950 F. 'J. sPANG 2,508,693

May 23, 1950 F. J. sPANG 2,508,693

PRocEss AND APPARATUS FoR FoRGING ABLE TOOL DRILL BITS Filed March 20, 1946 3 Sheets-Sheet 2 May 23, 1950 F. J. sPANG 2,508,693

- PRocEss AND APPARATus FoR FoRGING v cABLE Too. DRILL. BITs 3 Sheets-Sheet; 3

INVEJNTOR HIS ATTORNEYS Filed MarGh 20, 1946 Patented May 23, 1950 J Spang- Bitler; Bite v Application Marantao, 1946,,.seriaLNo. 6552739' This invention pertains to tlre'ma'riuctre of 'Wellr drillifigi bits andimorei' particularly' 'to prooedure'and' apparatus' sitble for-drop ham; merm'forgirg: of steel (lr'illF bitssuori' as used* iii: cable? tool 'or percussion: diillir'rg: That'fisthe. presentv invention deals' priiicipalIy-i with pro: cedurefor forging diill'ditsas d.i'stinguisl`ed` ffom; a 'rollingprocednr *I-'t-rcl'issi'cn` drill; bits'scfi as" isen 'the oli fie'ltisi comprise a, body; memberifiorlngtii h'avinzj a' iwhici'i" 'is 'g'erieral1`y composed' of" at. ccn- I nectoi`` pin" andie: caller?, Tlieislfink'or the-pin' collar' thereof* ordiarily 'termiiates' axtvrenoriu fiat portionthat;iscormectetothe ma'iif cutting; oodyjor* portion Voritiie memBer." I Tiius; broadwspeakin'g: 'the shttrilimay 'lie 's 'a'i'to-.also, inclie; the. wrench' 'flat' portion;l ''lftie` main b'ody. pare tion includes' length'wiseexteiriiiig` water courses along substantiall'plnar opposite 'fces thereof; h thet'represent'o: major trnsverse "axi df'flie.- body portion; Italsoihcefscutt'ihg ,porti'cnsfl that'A arefsomewliat' bove'lefi'i and' extentl 'lengthw'i'se' along sorrrewrizr:t convex* onpositefoes tliat; represent a` mioor" trznsverse* ax'is off' the body; portion; ftwill215e1emparrent'tilat'thecutteriiliaxiey oriolrill portion` of the Bit* aga'proximates a blocks letter- H' in section; this; portion* 'li'as' slightly; convex'slapeti'lcutter surfoestliatare'connected: byrelativey'tin conceive' rli'd'e' walls' w'ic'l'i! dfiietwater courses. j

"Theljits' used"ordrilngfiiurposes* in 'tlie ol fields are of* retlrer heevyco'nstruction,, mmm i'` Weight from' epproximatelyzo" t'ofiover' iimc; pounds: Drill tiit's ofltlie'perciission' type are of? ratlier:- massive* construction and are subject use*` to severe treatment; It* 'is 'thus' essenti thatitlieywheve a 'i'rif'c'riH metellie" F'structure orier'thaft 'they will' wear' eveh'lz and'2 ,remain intact throughout their; uselliie, which wm' involves a: 'considerable wearirrg: awayl of" theV material at the e'ncf. 'the in" 'the active operation: Iii myt E''teh't;4 #2j21`462' o'fctoher 1; 1*9ii0;1i'liave 'shown` aiproceireior oot'etining` uniformity' 'ofi struotre; `io''tiou-la;rly; froml the, stomipoint 'of 'the 'cutter :portion off tleJBit. ;Im a'c'cordence' 'with 'tie 'prcce'di're f``'''th,h lipsvu and coldi shuts'havebeen" elfninate; Themese'nt 'mprover procedure provides a; sulosttn'tiellizA uniform'metallie -structiremlb'rgtrie f'll'lengtiiN of' tl'ief'bit; whchinciiides the 'shark" anifwrench' flt p'ort'i'ons th'erec. 'That is; in' 'accorn'ce witif the present'proc'edire; 'the' fill lengtli; of", ieoe isi forgetf 'in .suc'ii' a manner' that the,v resulting" graiif ,s'truotinfe of 'the ;i i'ece'. closely' approx'i'mat'es that' lo a; 'rolle'if piece.

And: it lies" beer an" "obi ect of'the'present'fin vention'to lproviiie new' and improvedN f'crging' procedure andw4 tao-provide' Aapparatus 'for' carry, ing outA suchL procedireL in* tire' mtnuf.c't'ureA bff' percussiomflrillibits;

Another'object'of iiventior is'tvprod'lce'a: procedure'ior* forming: i'iiiL bits' which* involves". die forgii'g:5 tirebit'from endltemf K further-"and'more specific object' isttproe 'Heseand 1 other; objects o'fimy* invention appear to* those* ski-lied hr tiie'errt 'fronrtie--e scription oi 'the embodiment* chosen* Hfot` *bliv purpose off illust-ration,A as* well as from* 'ther' climsi In the drawings:

Figure` 3`- at similar view aiterf the* forgin'gI operation' has ie'en perfbrn'rej 'olrthw blank;

Figurewis a;--s-imiler"viefwfa-fterfiesli rasiieem' removed:

Figure* vii* is*- 'ar sirnitr '-viewf after the blamrcr'* pite-cehas-beenreversf-xi the tongs' for itimin? the -other leizc'i'secticn:

Figure* 'If isi 'a snilar Viewv after the *peceias* been s-accessivei-- farrdi progressively dick-forget!? from'its i-rtermedifite' portion to *the-ctttihgrezri'l*y o'f-ftlie other-'end *section-thereof 'Figureifl'iise similar :View off' a'r com'l'etiatl` per'ef cussi'on 1b'it-I after 'the selvage* 'and 'fish aver tbeen removed andz the` pin has been' threaded.,

Fures 1'0, TI and' lare transverse Sectional views taken along the lines X, XI and XII of Figure 9.

Figure 13 is a perspective view in side elevation of a device for shearing the flash from the bit.

Figure 14 is a view similar to Figure 9, but showing a pair of dies for forging the cutter portion of the bit in a closed relationship.

Figure 15 is a transverse section taken along the line XV-XV of Figure 14 and showing the piece in position ready for forging; Figure 16 is a similar section, but showing the dies in a .closed relationship after the piece has been die-forged.

As shown particularly in Figures 1 to 3, inclusive, I may start with a substantially square steel billet IO which may be held at one end by a pair of tongs II during subsequent operations.. I then,

block forge and die-forge one end section of the V sent or extend substantially parallel to the major transverse axis of the cutter blade body. The end of the blank has a selvage 2I which is removed blank, reverse the blank and block and die-forge is, I roughly produce a shank having a pin I5` and a, collar I4, a iwrench fiat i3, and may also produce an approximation of the beginning of the water course as shown at l'l, which are connected by a rectangular portion I2 to the main body of the blank lil. In this operation such end section of the blank is elongated, see Figure 2,y

to produce a somewhat rectangular-oval blank corrresponding roughly to the ultimate shape of such portions of a bit.

.In the next step, as indicated in Figure 3, I die-forge the thus roughly shaped portion of the blank in such a manner as to reverse the major andV minor transverse axes thereof and to further elongate it. In this operation, the wrench fiat I3l i completed., A portion of the rectangular section I2 is formed into what may be termed the beginning or upper end portion IG of the cutter blade.` That is,rI form water courses Il that, as shown, are substantially fully open to the wrench flat part I3, the convex cutter face or blade portions I9 and flash I8 extends longitudinally thereof. It will appear that 'the beginning f segment I6 of the cutter blade part is located intermediate the ends of the metal blank. In Figures 9, 10 and 11 and 12 I have shown dies which may be utilizedl in this connection and Which' will be described in more detail later.

The flash lil is then removed by placing the previously formed end of the blank on a box 35 having trimming knives 36 adjacent upper edges thereof which are spaced apart a distance substantially equal to the width of the section of blank from which the fiash is to be trimmed. For example, the knives 36 extend parallel for a portion of their length and converge at one end to the shape of the pin I5. When the formed end of the blank is in position a pusher block 31 is moved into contact with the upper face thereof to press it between the trimming knives and shear the flash I8 therefrom. After the flashhas been removed, the blank appears as shown in Figure 4. The blank is then reversed, see Figure 5, and isheld at its previously formed end by tongs I l.

In the next operation, the blank is block-forged at its 'end Ill into a rectangular shape whose major and minor transverse axes are Aat right anglesto the major and minor transverse axes of together with the fiash [8 to produce a completed bit cutting end 22, as shown in Figure 8. In this die-forging operation, I contemplate employing dies such as shown in Figure 14 of the drawings.

To finally complete the blank, as shown in Figure 8, I thread the pin end I5 in the usual manner, as indicated at 23.

Referring particularly to the dies of Figures 9 to 12, inclusive, it will be 'seen that they consist of upper and lower die portions, each of which is provided with dovetailed portions 45 by means of Which it may be attached to parts of a suitable hammer. Each of the die sections or halves is relatively long and exactly alike in shape or size, and each has die cavities25, 28, 29, 36 and 3I therein for shaping the blank from the form shown in Figure'2 to the form shown in Figure 3. I have indicated passageways 26 and fiashreceiving slots 21 at one end of the dies which extend transversely thereof, and side fiash formi ing passageways 26a and receiving slots 2'Ia which' extend longitudinally of the dies, see Figures lil, 11 and 12. The transverse flash-receiving slots 21 limit the longitudinal fiow of the metal at the pin end l5 of the drill bit member.

Referring particularly to the dies of Figures 14 to 16, inclusive, it is apparent that they substantially correspond to Vthe dies shown in my abovementioned patent, and like the dies of Figure 9, are designed to permit the formation of fiash j intermediate of and along longitudinal edges of 4'l of the fullers. All portions of the fullers 40 are formed on substantially the same radius, and as a result the front end 43 of the form is Spherelike in shape, and tapered end 4! slopes in all directions longitudmally. The walls of the opposed die halves are fiared at their rear ends to form an opening 42 which admits the blade portion of the blank without subjecting it to reworking. A s repeated blows are struck, the sides of the blank are bulged out and the metal is moved to fully fill thedie transversely and metal is caused to fiow outwardly through the passageways 46 into flash-receiving slots 41. It is apparent that as the dies approach closer 'and closer together, the excess metal of the blank must flow longitudinally from. the inner portion of the blank towards the outer end with the smaller portion of the metal overflowing to form a seal in the form 'of fiash IB, thus lcontlning the major portion of the side walls of the blank Within the die cvtsn An-Ipoiit'ed'out above; .flaSh' isormed: im. thepocketsforsltsffis anfi Emgsloyin'gsuch atpairroficfie'sg the:We'sterrt'ours'esTarmthe:cutting` surfaeee. are fbrmea on; the fb'ade-4 portion and: the: blank: of; the ena. section: is; advaneett :preegressvely along-' 2 the'sefi di'esi` With: ai slight 1 Ove'ri' lap between eaehoperatiomuntlit is completely' formed;

Flash: 18:t jfo'rn'ecii'alengthe: cutter: blase:y por: tiemofi the bit-member is removed-1 by: a: devieefi ('ctshbwmf that is-similartofthefdeviee ofFige urefil13; except that the. knives 36' extend;paralery alon' t 'length'sin=val-spabet1irelationship cbr'-i respondg-to th'el'engthzef the-major:transversei azsisbfisnchnertienvofs the:bit.

Inearryin'g 'out .my invention; I; preife'r tfute1-- abank; nhtn'etg. orrirntiablanki which will;J when: frgeranb el-cn'gaterrg corre'spenttto the desiree: legthl o the;z drill-btpecefl Tiatvs; the billet may: bef -l'e'ssfthan: oneethird: the length 'of thev ut'-nate shape: The' lengitudhal; flow or the off'the' blame: beforetthefettterbeswart ref pm nni-shed" bit; to3 be lftrrree therefrom plrovi'din'g; the blank-with a 'fer ngft'emp retare; welfare- (hate seementof cutter baae'ffi parti te tneother enn*erfthe manky saiaieie-roreing:opera:

ninese'gment offthefieutterblade 'part tefthefiother end i thereof'tef-alforr-1suehfthatf nta-*jer trans -f verse axs of the thu's-forged portion fi'thebankllext'en'dssubstant'-ttly` at right angles o'the ding?asubstantialylfinishea cttterfbade art'fron* the last-;mentionedprefirninarity .foi-gen 'pbrt'ionf of; `the blankv by' over-lap, agi-1 aef-forging oberwv` ti'ons. thatl progressifro i the previously' 'forre' segment ofl the: cutter bla-dei: fartiy of' the mentioned .porton 'o'f 'the blank `ini suoih'. a mamv`^ ner that a major transverse axis of the :outt'er blade part thus die-formed extendssubstantally ;at right=ang1es to the directibn of th'ermajon transverseaxis of theasorrespendingSs'ecnd-:neneV tioned `preliminar-ilysformed portion'o'f the blank; 6. A?methodfof.formingzafpercussioh Well-(hmf ing.: bit 'to :provider ae bit having' at -snbstanti'aly uniform -metafle' structure along:Y its full length-f.-

which comprises, providing a substantially rectangular metal blank of greater cross-Sectional area and lesser length than a finished bit to be formed therefrom; heating the blank to a forging temperature; initiating the formation, respectively from one end of and to a point somewhat intermediate the length of said blank, of pin end, collar and wrench fiat parts, and a beginning segment of a cutter blade part of the bit by block-forging such end portion of the blank; die-forging such initially formed parts to a substantially finished cross-Sectional form representing such parts in such a manner that major transverse axes of the thus die-forged parts extend substantially at right angles to the direction of major transverse axes of corresponding parts of the previously block-forged end portion of the blank, while forming thereon an intermediate flash which extends longitudinally along each side of such end portion and transversely across the pin end part thereof, and while causing the metal of the die-forged portion of the blank to flow longitudinally of the blank from the pin end part thereof; trimming the flash so formed; initiating the formation of a substantially complete cutter blade part of the bit by block-forging the other end portion of the blank to a form having a major transverse axis extending in a direction at right angles to the direction of the major transverse axis of a corresponding portion of the finished bit; die-forging the last-mentioned blockforged end portion of said blank to a substantially finished cutter blade cross-Sectional form such that the major transverse axis of the thus die-forged end portion thereof extends substantially at right angles to the direction of the major transverse axis of the corresponding part of the previously block-forged last-mentioned end portion of the blank, by overlapping die-forging operations that start from the previously-formed segment of the cutter blade part of the firstmentioned end portion of the blank and that continue substantially to the end of the lastmentioned end portion of the blank, while forming thereon an intermediate flash which extends longitudinally along each side of the last-mentioned end portion of the blank, and while causing the metal of the thus die-forged last-mentioned end portion of the blank to flow longitudinally thereof; and, trimming the fiash so formed. i

7. A method as defined in claim 6, wherein the second-mentioned end portion of said blank is held while the first-mentioned end portion is being forged, and the blank is reversed and the pin end part of said first-mentioned end portion is held while the second-mentioned end portion is being forged.

8. A method as defined in claim 6, wherein the die-forging operation on the first-mentioned end portion is efiected in such a manner as to provide water courses along the segment of the cutter blade part, and the die-forging operations on the second-mentioned end portion are affected in such a manner as to provide continuous water courses from the water courses of the segment of the cutter blade part of the first-mentioned end portion.

9. In a method of forging a metal blank into a percussion well-drilling bit member having eonnected cutter blade and wrench fiat parts of improved metallic structure, the steps of providing a metal blank of substantially shorter length and greater cross-sectional area than the finished bit to be formed therefrom, providing the blank with a suitable forging temperature while die forging a wrench flat part and the beginning of a cutter blade part having water courses substantially open to the wrench fiat part and, successively die forging a full cutter blade part with water courses by overlapping operations from the previously forged beginning of the cutter blade part.

10. In a method of forging a metal blank to provide a percussion well drilling bit of substantially uniform metallic structure along its length, the steps of providing a metal blank of greater cross-Sectional area and lesser length than a finished bit to be formed therefrom, maintaining the blank at forging temperature while block forging one end section thereof into a length somewhat corresponding to the desired ultimate shape of the bit and having a major transverse -axis that extends in a direction substantially at right angles to the direction of a major transverse axis of the corresponding end section of the finished bit, die forging said end section into substantially the ultimate desired shape of the bit and having a major transverse axis lat right angles to the corresponding transverse axis of the previously block forged end section of the blank, block forging the other end section of the blank into a shape roughly corresponding to the desired ultimate shape of the bit and having a tr-ansverse axis that extends in a direction substantially at right angles to the direction of a major transverse axs of the corresponding end section of the finished bit, and die fc-rging the second-mentioned end section to substantially the ultimate desired shape and dimensions of the finished bit, such shape having a major transverse axis at right angles to the corresponding transverse axis of the second-mentioned block forged end section of the blank; the die-forging of one of the end sections being effected in such a manner as to provide the beginning of a substantially finished cutter blade part with Water courses that is located substantially intermediate of opposite ends of. the'blank, and to provide a substantially finished wrench flat part adjacent thereto and to which its water courses are open; and, the die forging of the other end section being eifected by overlapping operations that are started from the beginning of the cutter blade part and that continue along such other end section to form a substantially complete and finished cutter blade part having continuous water courses along.

ll. In a method of forging a metal blank to provide a percussion well drilling bit of substantially uniform metallic structure along its length, the steps of providing a metal blank of greater cross Sectional area and lesser length than a ilnished bit to be formed therefrom, maintaining the blank at a forging temperature while block forging an end section thereof into a rectangularoval shape portion corresponding to preliminary pin, collar, wrench fiat parts and the beginning of a cutter blade part of the finished bit; die forging the rectangular-oval shaped portion into conic, rounded and fiat portions corresponding to substantially finished pin, collar, and wrench flat parts and the beginning of a cutter blade part with water courses of the bit, such that major transverse axes of the substantially finished parts extend in a direction at right angles to the direction of major transverse axes of the preliminary parts; reversing the blank, block forging the other Sectional end thereof into a rectangular shape having a major transverse axs at right angles to a major transverse axis of the substantially finished beginning of the cutter blade part of the bit, and progressively and successively die forging the second-mentioned end section from the beginning of the cutter part and its water courses to the end of the second-mentioned section of the blank to form a substantially finished cutter bl-ade part having Water courses extending longitudinally along its opposite faces that represent a major transverse axis of the cutter part and With cutter edges extending longitudinally along convex faces that represent a transverse minor axis of the cutter blade, said lastmentioned die forging being effected in such a manner that the major transverse axis of the substantially finished cutter blade part extends in a direction at right angles to the major transverse axis of the corresponding previously blockforged end section of the blank.

12. A percussion well-drilling bit of substantially uniform metallic characteristics along its length having integrally connected die-forged, pin, wrench flat and blade parts therealong, said blade part having walls defining water course depressions extending longitudinally along said blade part from a cutter end thereof to said wrench flat part, said water course depressions being fully open at their iongitudinal ends to said wrench flat part and to a cutting end of said blade part, and said water course depressions being of substantially uniform transverse Width along the length of said cutter blade part and being at their open ends of at least as great a width as along the length of said cutter part.

13. A pair of opposed die blocks for simultaneously die-forging pin, colla and wrench flat parts, and a segment of a cutter blade part along one end of a longitudinal metal block to form a percus- 10 sion `well-drilling bit; one of said die blocks being adapted to be mounted on a hammer and the other being adapted to be mounted on an anvil; an opposite face of each die block having a die cavity open to one end thereof, extending longitudinally therealong, and closed to the other end thereof; longitudinal passageways along opposite sides of the die cavity of each die block and open transversely thereto; longitudinal nash-receiving slots of greater depth than the longitudinal passageways, along outer sides of the longitudinal passageways, and open transversely thereto; the die cavity of each die block terninating in a semi-comical Wall portion at the closed end thereof; a transverse passageway along a converging end of said semi-conical wall portion -and open longitudinally thereto; a transverse nash-receiving slot of greater depth than the trans-verse passageway, along said transverse passageway, and longitudinally open thereto; and, each die cavity being constructed to define half of a complete die cavity for the metal blank.

FERDINAND J. SPANG.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PA'I'ENTS Number Name Date 435,855 O'Leary Sept. 2, 1890 '758,041 Barclay Apr. 26, 1904 879,631 Gregson Feb. 18, 1908 1,474,516 Eicher Nov. 20, 1923 1,680,327 Eicher Aug. 14, 1928 2,216,462 Spang ..1.. Oct. 1, 1940 

